1. Field of the Invention
The present invention concerns a method and a device to take the end of a roving or sliver from a rotating cop and carry it to a predetermined position, for example in correspondence with a textile machine, such as a spinner, in a completely automatic way and without damaging the roving or sliver.
2. Description of the Prior Art
At the present state of the art, the technique of machine feed envisages that the operation of seizing the end of the roving or sliver from a rotating cop and carrying it to a grasping device in a textile machine (for instance, the drawing rolling mill of a spinning machine), while simultaneously unwinding part of said roving or sliver, be performed almost completely manually. The automation of such an operation is therefore advisable not only for obvious economical reasons, but also for more strictly technical considerations, since the operations upstream and downstream of such devices are already completely automated and thus the presence of such a manual step may cause problems related to productive times within the whole process.
However, the reasons for having the manual step instead of an automated step is simple. The utmost care must be taken in seizing the end of a roving or sliver and moving it to another location; quite unlike the moving of yarns and similar large threads. As those skilled in the art can appreciate, rovings or slivers are quite delicate, and thus easily damaged. The construction and arrangement of certain devices for moving yarns or other larger threads has been found to be unsuitable for use in connection with rovings or slivers because the rovings or slivers are easily damaged when seized (if seizing is even provided for in such devices) and/or when moved or unwound. The cause of such damage can be as simple as the use of a relatively large burst or jet of air, as is typically employed in such devices to effect the movement of the yarn. Such a large burst or jet of air is required because of the typically narrow mouth sections employed by conventional devices.
There is therefore the need of a method and a device capable of automating the operation of drawing the end of a roving or sliver and carrying it to a predetermined position in association with a textile machine without damaging the same. There is also a need for this method and device which are adapted to seize and move the end of rovings on successive rotating cops without interfering with the unwinding of the rovings from previous cops.